Most agriculturally-cultivated blackberries are known as “floricane”-fruiting blackberries. Floricane blackberries are primarily produced in Oregon, which accounted for a 2009 harvest of approximately 42.6 million pounds. The canes of floricane-fruiting blackberries have a two-year life cycle. In the first year, the canes emerge and form a vegetative structure with leaves and buds at each node of the cane. These canes must then weather a period of cold temperatures in the winter before they develop further.
In the second year of the canes' life cycle, flower shoots form from the buds that developed the previous year. At this point the canes are considered to be “floricanes” because the over-wintered canes now can develop reproductive flower shoots. The flowers on the floricanes continue to develop and eventually mature into fruit—which ripens during the summer of year two.
Although floricane-fruiting blackberries are well-suited for production in the Mid-Atlantic area, growers in the Mid-Atlantic area have been reluctant to plant floricane-fruiting blackberries because the fruit is only produced in the second year, and a harvestable crop is only produced during a relatively short time period. Additionally, floricane-fruiting blackberries are vulnerable to the long periods of extremely cold weather that sometimes strike the Mid-Atlantic, Midwest, and Northeastern United States. Extremely cold weather can severely damage or destroy mature plants. These limitations render floricane-fruiting blackberries less desirable than many competing crops which may produce multiple harvests or may continuously produce fruit throughout the growing season—and are not as susceptible to cold weather.
Recently, new varieties of blackberry plants designated as “primocane-fruiting” blackberries are being used in commercial production. Unlike the more flexible stalks of floricane-fruiting blackberries, primocane-fruiting blackberries have more rigid stalks that, left undisturbed, can grow vertically to 10 feet or more. Flowers and eventually fruit develop primarily on the ends of the vertically-extending primocane shoots. Although the primocane-fruiting blackberries develop fruit every year, the yield per plant is relatively low. To increase fruit yields, growers prune the ends (i.e. “tip”) the ends of each primocane so that one or two side shoots emerge. Clusters of fruit eventually form on the emerging side shoots.
The need exists for a process that increases the amount of blackberry fruit that can be produced per season on current year's growth of primocane-fruiting blackberries. The primocane-fruiting blackberry production system described herein includes a flexible trellis that periodically reconfigures the blackberry primocanes so that the primocanes extend horizontally. The horizontally-extending primocanes produce flowers and eventually fruit along the entire length of the horizontally-extending primocanes—thereby maximizing blackberry flowering and ultimately fruit production. Further, the horizontally-extending primocanes concentrate blackberry fruit production in a zone that is near ground level rather than at the elevated heights normally seen during conventional primocane fruit production. The lower height of the fruit produced in accordance with the method and apparatus described herein enables the fruit to be harvested with conventional machinery that cannot be efficiently utilized with taller vertically extending primocanes. The lower height of the fruiting primocanes also facilitates hand-picking the fruit.